1. Field of the Invention
The present invention relates to systems and methods for obtaining optimized radiation dose deposition, and more particularly for automatically generating individually optimized treatment strategies for multiple treatment goals on a single patient, multiple patients or treatment sites.
2. Description of Related Art
The goal of radiation therapy is to deliver a high, curative dose to a tumor, while minimizing the dose to normal tissues and limiting the dose in critical healthy structures to their radiation dose tolerance. In the past several years, significant advances have been made to identify and characterize in three dimensions the patient's tumor, as well as normal, sensitive structures, and then deliver a high dose that conforms to the three-dimensional volume of the tumor. Enabling imaging technologies are computed tomography (CT) and magnetic resonance imaging (MRI) scans of the body, which are now a common part of radiation therapy planning. New methods for specifically identifying the location of tumors and cancerous tissue include magnetic resonance spectroscopy (MRS) and proton emission spectroscopy (PET). In addition, computer-controlled beam modifiers, such as multileaf collimators and dynamic wedges on linear accelerators offer the ability to both shape the radiation beam and sculpt the beam profile in three dimensions. Sculpting the beam profile is accomplished using a technique referred to as intensity modulated radiation therapy (IMRT). Incorporated in multiple-beam plans, IMRT can deliver a complex map of dose, in which the therapy can be made to conform closely to the patient's tumor.
Two critical links required for accurate delivery of the optimal conformal therapy plan are the ability to accurately predict the dose distribution in the patient (given a dose-delivery configuration), and the ability to optimize the treatment plan or dose delivery configuration to yield the most advantageous dose distribution for the patient. The PEREGRINE dose calculation system, developed at Lawrence Livermore National Laboratory, uses Monte Carlo transport calculations to provide highly accurate three-dimensional dose calculation for radiation therapy. The FALCON automated planning system, described here, uses these accurate dose calculations to identify and prescribe the treatment plan that best meets the planners treatment objectives.